Feed-roll for leather-skiving machines.



PATENTED DEC. 31, 1907.

HIRTH. FEED ROLL FOR LEATHER SKIVING MACHINES.

APPLICATION FILED 00122. 1906 v INVENTOH 5) Q A (I 1 ATTORNEYS WITNESSES THE nanny; pn-rns cm, WAsHINGrnN, o. c.

ALBERT HIRTH, OF OANNSTATT, GERMANY.

FEED-ROLL FOR LEATHER-SKIVIN G MACHINES.

Specification of Letters Patent.

Patented Dec. 31, 1907.

Application filed October 22, 1906. Serial No. 339,969.

To all whom it may concern:

Be it known that I, ALBERT HIRTH, a citizen of the Empire of Germany, residing in Cannstatt, in the Kingdom of Wiirtcmberg, in said Empire, have invented certain new and useful Improvements in Feed-Rolls for Leather-Skiving Machines with Ring-Knives,

of which the following is a specification.

. This invention relates to improvements in machines for skiving and splitting leather and similar materials by means of a ringknife, and relates more specifically to the improved feed-roll for the material that is fed to the ring-knife so that the uniform forward feeding of the material over its entire width is obtained; and for this purpose the invention consists of a feed-roll for skiving machines, whichis composed of several individual rollers which are rotated independently of each other on their shaft in such a manner that the circumferential velocity of said rollers in contact with the material corresponds to the linear velocity of thesame, and the invention consists further of certain details of construction which will be hereinafter described and pointed out in the claim.

In the accompanying drawings, Figure 1 represents a vertical longitudinal section through my improved feed-roll for skiving machines in which the material to be skived maybe conducted in any desired are over the cutting edge of the ring-knife, and Fig. 2 is a similar section of a feed-roll for skiving machines in which the arc of the material to be skived is carried in an arc of definite form or in a straight line parallel with the axis of the ring-knife, over the ringknife.

Similar letters of reference indicate corresponding parts in the figures of the drawing.

The feed-roll can be arranged at the inside or at the outside of the ringknife, or at both sides of the same, as shown in Figs. 1 and 2. In the outer feed-roll, shown in Fig. 1, a number of individual rollers 1), 6 b are placed. on a common shaft (Z and retained by friction yieldingly on the same. The smallest roller 1), which has to be turned with a greater circumferential speed, is actuated directly from theshaft, but can be shifted on the same. In the same manner, two friction-bearings e, which turn in ring-shaped bearings c of an arm a that swings around a fulcrum n, are held under the frictional influence of a helical spring-f, which turns with the shaft (Z and. is retained thereon by a screw-nut a placed on the threaded end of the shaft. The rollers 6 b can turn on the shaft d when the friction which takes place between the individual rollers and the friction-bearings e is overcome. During the rotation of the shaft (Z, the circumferential velocity of the middle roller 6 determines the linear velocity of the material w, and the circumferential velocities of the rollers b 6 which are moved by-friction in the same direction, adapt themselves thereto, whereby these rollers remain correspondingly behind the middle roller. The force that is exerted on the rollers 5 b by the rotary motion of the shaft can be altered at will by changing the tension of the spring f, which is accomplished by the turning of the screw-nut u or by shifting the shaft d in the longitudinal directionf In the inn er feed-roll, the yielding connection of the rollers with the shaft is carried out in a somewhat different manner than in the outer roll. Besides the friction-bearings e, which are located in the ring-shaped bearings 0 are arranged the rollers b b 6 which are clamped together by the pressure of the spring f and in addition thereto frictionboxes 9 are employed, which are shiftable on the shaft (1 but which cannot be turned relatively to the same, while the rollers b, b, b can all be turned relatively to each other and to the shaft al as soon as the friction, which takes place between the rollers and the disk-shaped ribs h of two adjacent friction-boxes g, is overcome. On turning the shaft (1, the individual rollers, which are all turned in the same direction, glide towards each other in such a manner that their circumferential velocities correspond to the linear velocity imparted to the material to be operated on. It is immaterial whether the material is conducted in 'a straight or curved form over the cutting edge of the ring-knife, inasmuch as all the rollers can give slightly towards each other. Owing to the driving action imparted to the shaft of the feed-roll which is located above the ringknife, the middle roller b cannot give, but notwithstanding this it is possible to conduct the material in an are as the rollers which are located at one side of the middle roller receive a gradually diminishing motion, while the rollers on the 0p osite side of the same receive a proportionate y increasing motion.

In Fig. 2, the middle roller 1) is rotated by a shaft d, while the adjacent rollers 6 b are rotated by means of connecting-sleeves i and 7c which are placed concentrically with each other on the shaft d. On the ends of the.

shaft (1 and the sleeves i and k are mounted gear-wheels Z, p, g which intermesh with gear-wheels 1", s, t that are keyed to an auxiliary shaft 0. The dimensions of the gear Wheels Z, p, g and r, s, t are so chosen that the circumferential velocities of the rollers 11, bl, b are equal to the feed-motion that is to be imparted to the piece of leather or other materlal to be operated on. When the circumferential velocity is made equal for all the rollers the work-piece is moved forward in a straight direction, but in an are when the rollers, commencing at one side, are moved with gradually increasing circumferential velocity. According to the size of gear-wheels, it is therefore possible to conduct the working-piece in an arc of definite but uniform shape over the cutting edge of the ring knife. This construction of the feed-roll is adapted for use only in such cases in which the work-piece is to be fed either in a uniform are or in a straight line over the edge of the ring-knife.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

In a skiving machine, the combination, with a ring-knife, of an inner convex feed-roll divided into a number of individual rollers of different diameters, an outer concave feedroll also subdivided into a number of individual rollers of different diameters, and shafts upon which said feed-rolls are supported.

In testimony, that I claim the foregoing as my invention, I have signed my name in presence of two subscribing witnesses.

ALBERT HIRTH. lVitnesses RUDoLF BREGHT, ERNST ENTENMANN. 

